Spray gun



' Dec. 4, 1928.

G. A. MUELLER SPRAY GUN Filed April 7, 1927 Patented Dec. 4,

f UNITED ST A TES PATENTQIFFIOCE.

GODFREY A. MUELLER, or ronvr rnnonronro, Assrsuon f rnn DE VILBISS com-I'ANY, OF TOLEDO, OHIO,

.A' CORPORATION OF OHIO.

' srRAxcUN.

Application filed April 7,

i v This invention relates to spray-guns of the .type commonly known asair-brushes and used to atomize and spray coating materials.

Inspray-guns of this character, separate provision is made for feedingboth the material to be sprayed and the atomizing air or 'motive fluidto the spray bead, and both are controlled by independent valves thatare commonly actuated to have opening movements by a single operatingmeans. It is desirable in the use of such spray-guns to have the airvalve completely opened or opened to a predetermined maximum adjustableextent before the material control valve is opened,"

'- fore used so that the initial portion of the material spray may be asfinely atomized or subjectedto the samevolume and pressure of atomiz- VVing air as thebalance of the spray, thereby preventing the stopping andstarting of the spraying operation from being noticed on the work. Acontrol means of the type heretois' illustrated in application for U. S.Letters Patent Serial No. 682,700, filed December 29, 1923 now PatentNo. 1,613,588

of Jan. 4, 1927. i

The object of the invention is the provision of simple and efiicientcontrol means for the motive fluid and materialvalves, which means isoperable by a continuous pull thereon or movement thereof in onedirection to first open the motive fluid valve to its full extent or toits maximum adjusted position and their I embodying the inventlon wlth apart 1n central longitudinal section and with the valves.

to open the material valve to its full extent for which adjusted, sothat the desired and resultant advantages may be obtained.

' The invention is fully described in the following specification andone embodiment thereof illustrated in the accompanying drawing, inwhich,-

, Figure 1 is a side elevation of a spray-gun and operating means innormal position. Fig; 2 is a fragmentary side elevation of the spraygunwith the operating means in the position which it assumes when themotive fluid valve is fullyopened and the material control valve isclosed, and Fig.- 3 is a similar view thereof with the coeratingmeans inthe position which. it takes when both valves are fully opened.

Referring to the drawings, 1 designates the body or stock portion of aspray-gun embodying the invention, 2 the spray-head unit carried by theforward endof said body,

and 3 .1927. Serial No. 181,-6o.

projecting down from the rear end The body 1 is provided with apasthrough a passage 5, in the present instance,

and other passages1(not shown) with the air discharge passage of thespray-head, aswell understood in the. art. A valve 6 .is' disposed inthe passagefl and is held normally seated against a restricted portionof the'passage by a compression spring 7 at the forward end thereof.stem .8 projects from the valve rearwardly through a guide portion ofthe body 1 and into an open space 9 in the body, which space is openatits bottomv without the underside of the body; I l

The fluid discharge passage of the sprayhead 2 is controlled by a valve,the stem 10 of which projects rearwardly from the sprayhead forreciprocatory movements therein and with its-rear end'projecting underthebody space 9 and bearing against aplunger 11 which normally holds thevalve in seated position, This plunger has reciprocatory movements in asocket 12 in the rear en of the body 1 and is normally held in forwardlyprojected position by a coiled compression spring 13, the forward end ofwhich bears against the plunger while the rear end thereof bears againsta stop screw 14 having a shoulder 1&1: for coacting with the plunger. 11to limit its rearward movement. Nothing new. is claimed for'any of thestructure'so far described, as it is common in spray-guns heretoforeused.

The trigger member 15 by which the valves are operated is disposedinadvance of the inner end portion of the handle 3 and has,

19 which bear against shoulders 20 on the respective sides of theenlargement 16 so as to exert a rearward pull or thrust on saidenlargement and the valve stem 10 when the, trigger is drawn rearwardly.a

Athrust block 21 is mounted on the pin 17 intermediate the arms of thetrigger'15, and

f I I upon a forward movement of'the upper end portlon of the'trig er isintended to bear a ainst the rear en of the valve stem 8 to i e ect anopening of the associated valve 6.

. and/limit the inward movement of the arm and valve. a

It is evident in the use of this control that after a rearward valveopening pull is exerted on the lower end of the trigger the trigger willrock with the portions 19 and 20, serving as a fulcrum therefor, andeffect a forward opening movement of the valve 6 to the full extentallowed by the adjusting sleeve This is accomplished by reason of thespring 13 being of greater tension than the spring 7, so that the valvestem 10 will becaused to stand still while the valve 6 is bein movedtofull open position. allowed by adjusting sleeve 23. During thismovement, the pin 17 moves to the limit of its forward movementin'the'slots 18 in the body 1 or until the head 24-. is stopped bysleeve 23,- and when the move- 'ment of thepin has stopped either by itsengagement with the forward end walls of said slots 01' by engagementofthe stop 24 with the rear end of the adjustable guide sleeve 23through which the arm 22 pro ects, a continued pull on the trigger-15will cause it to rock about the pin 17 as a fulcrum and to cause arearward movement of the valve stem 10 against the tension of the spring13. In other words, during the opening movement of the air or motivefluidvalve 6 the trigger will act about its point-of engagement with thevalve stem 10 as a fulcrum and when the air valve has been opened to thepermissible extent, the pin 17 will then act as a fulcrum for themovement ot the trigger which effects the opening movement of thematerial control valve. I

, Inasmuch as the invention resides entirely in the operating means forthe two control valves ofthe gun and nothing new is claimed 2 .for theother parts thereof, as for. instance .capable of numerous theconstruction of the spray-head 2 which may be of any suitable form, suchparts are not shown or described in detail.

I wish it understoodthat my invention is not limited to any specificconstruction, arrangement or form of the parts, as it is modificationsand changes without departing from the spirit of the claims.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent is: 1

, agent valve,

" 1. In a spray-gun, a bddy, two separate control valves one for themotive agent and the other for the material to be sprayed, said valveshaving opening movements in opposite directions, separate yieldingclosing means for the two valves acting with greater force on thematerial control Valve than on the" other valve, a sleeve member carriedby the body in spaced relation to the motive agent valve for adjustmenttoward and awa from the same, a plunger carried and gui ed forreciprocatory movements b said sleeve member and having coaetion wit themotive agent, valve to open the same when moved in one direction, saidlunger havin a stop part for coaction with t e sleeve mem er to limitthe valve openin movement of the lunger, a. trigger mem er pivotallcarried by said plunger and having a fu crum point on the materialcontrol valve whereby, upon a m vement of the trigger in one direction,it will A fulcrum on the material control valve and.

actuate the plunger to open the motive agent control valve, the limitpermitted by the adjustment of the sleeve member and then during acontinued movement of the trigger to fulcrum on the plunger and impartan opening movement to the material control valve.

2. In a spray-gun, a body having a bottom recess, a motive agent controlvalve projecting'into said recess, a material control valve projectingfrom" the body below said recess,

separate means 1 for normally maintainin each valve in closed positionand acting wit greater force on the material control valve, a sleevemember threaded in the rear wall of said recess for axial adjustmenttoward and .away from the motive agent control valvefa plunger carriedfor limited reciprocatory movements by saidsleeve member and adapted toact against the motive agent valve to open the same, a trigger extendingup into said recess and pivoted to said plunger and having a part belowthe plunger in rearward thrust 'coaction with the material valve wherebyan operating movement ofthe trigger will first cause it to fulcrum onthe ma: terial valve and impart predetermined valve opening movement tosaid plunger and then during a continued movement to fulcrum on theplunger and impart predetermined opening movement to the material valve.

3. In a spray-gun, a body, two separa control valves one for the motiveagent'and the other for the material tobe sprayed carried by the body,said valves having opening movements in opposite directions, separateyielding closing means for the two valves acting with, greater force onthe material control valve than on the other valve, a reciprocallymovable plunger carried by the body in adjacent relation to the motiveagent valve and operable when moved in one direction to impartopeningmovement to the motive an adjustable stop for the pivotally carried 'b'pliinger to limit the permissible valve opening movements thereof, atrigger member the plunger and having afulcrum' point a apted to havethrust contact with the material control valve'in valve openingdirection whereby upon a movement of the trigger in valve openingdirection it will fulcrum on the material control valve actuate theplunger to open the motive agent control valve to its full permissibleextent and will then, during a continuing movement, fulcrum on theplunger and impart an open movement to the material control valve. Intestimony whereof I have hereunto signed my name to this specification.

- GODFREY A. MUELLER.

